HAVE A 97 1-TONw/ 4:10 rear end want to change to 3:72 or prefer a 3:55.What kind of problems will run into? Or is it a can do thing?

 

The only things I can think of that will affect you is this:

- year of truck it came from, the TPS on the Dana80 tranny is different for some years, not compatible.
- DRW versus SRW, DRW Dana80 axle is shorter by about 2" than SRW axle.
- Limited-slip versus non-limited-slip. Either will fit, but affects drive traction you get on the ground, i.e., 2 wheels versus 1 wheel.

I got a Dana 80 axle from a wrecked 94 Ram 3500 dually for my 98 Ram 3500 dually. Axle fit perfectly, swapped brake components, ect. Only problem was the TPS mounted in the top of the diff. Mine would not fit in the mounting hole of the 94 axle because of a flange around the mounting hole, so I had to sue the 94 TPS. The wiring harness connector was different as well, had to splice the wires.

 

You will need to change the speedometer gear on the transfer case to the correct tooth count, so that your speedometer will be calibrated correctly for the gear ratio. If you can, get it from the donor truck.